Motorized handsaw



3 March 5, 19.29. F. L. WEED MOTORIZED HANDSAW 2 Sheets-Sheet 3 Filed Jan. 12, 1926 I\ I g I /lr V47 7 \w E h $1 .8 3 Na a a 31 .R g.

IVENTOR 'E'ankL.M ed

WITNESSES ATTORNEYS Patented Mar. 5, 19 29. t

an" seas;

FRANK LE SLEY WEED, F QUINCY, MASSAGHUSETTS.

I MOTORIZED HANDSAW.

Application filed January 12, 1926. Serial No. 80,767.

The present invention relates to improvesizefor manual manipulation, andcapable of being operated by steam, compressed a r, or

other motive fluid.

It is an object .of the present inventionjto provide a saw of this general character which will be extremely simple and practical in construction, rugged, durable and eflicient in use, and lending itself to the requirements of economical manufacture, assembly and operation.

VVi'th the above noted and other objects in view, the invention consists in certain novel 7 features of construction and combinations and arrangements of parts, as will be more fully hereinafter set'forth and pointed out in the claims. The invention may be merc fully understood from the following description in connection with the accompanying drawings wherein- F ig. 1 isa'broken View. in side elevation showing a saw and motorunit embodying the present invention. 7

Fig. 2 is an enlarged transverse sectional view on the line 2P2 of Fig. 6.

Fig. 3 is a similar view on the'line 3-3 of Fig. 6.

Fig. 4 is a longitudinal sectional view.

through the main valve chamber on theline 44ofFig. 6. Y Fig. 5 is a longitudinal broken sectlonal view taken in a vertical plane through the power cylinder and valve chambersor cylinders, and showing the power piston at one end of its stroke.

Fig. (Sis a view similar to Fig. 5, but showing the piston and the valves in their opposite extreme positions: I

In the drawings I have used the reference character 10 to designate a power cylinder including removable flanged heads 11 and 12, coupled together by tie bars 13, the extenslons 14 of which provide a frame which guides the movement of the saw 15. The extensions 14: of the tie bars are coupled together by block 16 which guides the'movement of-the' saw blade, and the inner end of the saw is bolted"- or otherwise suitably secured at 17 to a cross head 18 sliding'on the frames 14, and directly coupled to an extension 19 of the ma n hollow piston rod 20 for the main power p ston 20*.

The removable head 12 I is preferably formed as an integral casting with a pair of cylindrical valve chambers or casings 21 and I 22. The ends of these chambers are closed by a plate 23, and the chambers house a pilot valve 24, and a mainvalve 25 respectively. Eachof these valves is 111 the nature of a sliding member actuated'by the motive fluid for 7 the piston 20 in a manner to be more fully hereinafter described. The pilot valve'24L- carries an operating extension 26 formed with a tappet 27 disposed within the hollow piston rod 20. This tappet is alternately engaged by the piston 20 and by the end wall 27 of the recess in the piston rod to .efl:'ect'positive shifting of thepilot valve. The pilot valve is also formed with anextension 28 at its op posite end guided in a suitable bearing 29 in the plate 23.

Before proceeding with the description of I ithe'details of the valve mechanism, and the means by which the pilotvalve and main valve control the supply of motivefluid to the power piston, it may be noted that this valving is subject to a wide variety of strucg tural variations, and that any suitable type of valve mechanism might be substituted for "f the particular mechanism herein illustrated.

It is of course desirable that the valve mechanism be as simple and as light in weight as f practicable, (and I have found the illustrated mechanism well suited to the requirements of practical-use. r i

Pilot valve 24: is formed with four enlarge- I ments or'fianges 30,31, 32,33 wh ich'snugly fit the cylindrical chamber 21, and restrict the flow of motive fluid longitudinally'of the ipilotvalve. The main'va1ve'25 is preferably somewhat larger'than the pilot valve, but is similarly. constructed, including 7 cylinder fitting fiang'es 34, 35,36 and37. The main valve 25 however, carries no guiding exten- 'sions atits end, butis freely movablein its cylinder 22 under the iiifliienceof the motive 'fluid, as will be more fullyhereinafter set forth. 1

A steam 'supply' pipe 40 communicates 1 a steam inlet port 41 inthe wallo-fmain'valve cylinder'22. This port preferably enters the H cylinder approximatelyat the center thereof, fso'that in either position of the main valve,

the" inlet port will'deliv'er steam intoltlie annular chamber 42'defined by' the valve 25,

the'walls of the cylinder 22, and the two 1 flanges 35, 36. V Branching from the'main steam pipe 40. is asteain inlet pipe4c3Kentering a port 44' in the pilot valve cylinder 21, v ,7 port 44 beingvertica'lly aligned'with the port 41. Steam entering the pilot valve cylinder through the port 41 always passes intothe annular chamber 45 defined by valve 24, cyllnder 21 and flanges 31, 32. I

Steam-exhaust ports 46, 47 are provided in the pilot valve cylinder on opposite sides of the inlet port 44. Exhaust port 46 is always in conm'iunication with the annular ch amber48 I defined by the flanges 30, 31, and the exhaust valve flanges 34,

port 47 is always in; communication with the One end of the cylinder 22com1nunicates with the cylinder 21 through a steam passage 54, and the opposite endoi the cylinder 22 communicates with the cylinder 21 through a steam passage 55. Communicationthrough one or the other of these steam passages is always out ofli by the pilot valve 24. With the parts in the position of Fig. 5, it will be seen that there is free communication from inlet port, 41 through chamber 45 and passage 54 to the rear end of cylinder 22'. Flange 32.

cutsoi'lcommunication between the port 41 and the other passage 55. the position of'Fig. 6, the reverse is true, passage 55 providing free steam communication between the cylinders 21, 22, and passage 54 being cut ofi'by the flange 81.

,Thecr'ank end of the main power cylinder '10 communicates with the main valve cylinden 22 through a steam port (Figs. 5 and 6), while the head end of the power, cylinder communicates with the main valve. cylinder 22 through a steam passage 61. It will be noted that one or theother of the steam'passages 60, 61 will always be cut off from the steam supply port 41 of the main valve cylinder. lllith the parts in the position of Fig. 5, 'theflange 35 prevents the passage of steam 7 from theport 41 through the passage 60, and

with the parts in the position of Figs. 4 and- 6, the'flange 36, prevents the passage of steam through the passageway 61.

The steam. exhaust ports 50, 51 of the main" valve cylinder deliver exhaust steam through passageways62,63, to a common exhaust pipe 64. The exhaust ports 46,47lrom the pilot valve cylinder deliver steam through passages. 65to' the passages 62,63, thence to the main exhaust pipe 64. V J p The operation of the deviceis substantial ly as follows. With the parts in the position of Fig. 5, the tappet 27 has just been engaged by the shoulder 27 to shift the pilot valve 24 to its extreme rearward position. As the pilot valve reaches this position, the passageway 54 isopenechand steam entering through With the parts in the port 44 passes through chamber 45 and passageway 54 behind the rearend of the main valve 25. It will be recalled that steam is always entering the chamber 42 around the main valve, but since steam pressures on the flanges 35 and 36 are equal, the steam enj 'tering through the port 41 will have no tendency to shift the valve, The steam entering behind the rear end of valve 25 will shift the'valve to the position of Fig.i-5, it'being borne in mind that passage 55 is cut oil from the steam port 44, and serves as an exhaust passage through which the steam at the front I 1 end or the piston escapes to exhaust through the port 47. As the ma n valve reaches .the

position of Fig. 5, the flange 35 cuts off the passage 60 to the power piston, and the flange 36 uncovers the inletend of the passage 61. Thus the steam will pass through the passage 61 into the head end of the power cylinder, and will shift the power piston from the positionot Fig. 5 to the position of Fig. 6'.

As the power piston reaches the position of Fig. 6, the tappet 27 is engaged by the pis ten, reversing the position of the pilot valve. At this 'tin're, the flange 31. openspassage 54 to the exhaust port 46 and opens passage 55 to the incoming steamtrom chamber 45.5.

Thus the steam flowing through passage 55 into the front end of the ma n valve cylinder reverses the position of the main valve. As

the position of the main valve is reversed, the flange 36 cuts off the passage of steamthrough passageway 61, and opens the passage 62" to the crank end of the power cylinder, whereby a reverse movement of the power piston is effected.

' It will be noted that the passages 60 I 61, as well as the passages 54 and 55, serve alternately as supplyand exhaust passages. In Fig. 5, the passage 60 is cut off from .inlet port 41,andsteamis exhausting from thispas-- V sage through the chamber '52 and exhaust port 50. In Fig. 6, the reverse is true, inasmuch as the passage 60.1s1n directcommunication. with the steam inlet port 41.

I have referred throughout the specificatlon to steamports and steam passages, but it Wlll be obvious that the. device might be run equally well on compressed air. When steam is used as a motive fluid, some suitable v handle means .(not shown)="is provided for".

manually grasping the tool and guiding the movement'of thesaw. When compressed air is used as a fluid medium, the tie bars 13 may conveniently serve as handles,-orthe casting which encloses the valve mechanism .may be used as a handle. In. any event it will 1 be preferable to have the intake and exhaust;- pipes 40 and 64 connected. throughflexible hoseleads to a suitable sourceof supply ofzl steam or compressed air.

Inthe descriptlon of operation I have reterredto the pilot valve as being positivel Y operated by the lost motion connection be-- tween the extension 26 and the piston rod 20. It will be quite obvious that this positive operation need not be for the entire stroke of the pilot valve, and that it Will only be necessary to initiate movement of the pilot Valve and crack ports 54, 55 in order to effect fluid actuated shifting of the main valve 25.

It Will be evident that various changes and alterations might be made in the general form and arrangement of parts described Without departing from the invention. Hence I do not Wish to limit myself to the details set forth, but shall consider myself at liberty to 7 make such changes and alterations as fairly fall Within the spirit and scope-of the appended claims.

I claim:

1. A motorized hand, saw including a motor cylinder, flanged heads at the, ends oi the motor cylinder and tie bars connecting the heads and disposed at the exterior. of the cylinder, said tie bars projectin Well beyond one end of the cylinder to constitute guides, a cross head reciprocating on the projecting ends of the tie bars and a saw carried by the cross head, said saw being operatively eon neoted to amotor Within the cylinder.

2. A motorized hand saw including motor cylinder, flanged heads at the ends of the motor cylinder and tie bars connecting the heads and disposed'at theeXterior of the cylinder, said tie bars projecting Well beyond one end of the cylinder to constitute guides,

a cross head reciprocating on the projecting ends of the tie bars and a saw carried by the cross head, sald saw being operatively con cylinder, flanged heads at the ends of the motor cylinderand tie bars connecting the heads and disposed at the exterior of the cylinder, said tie bars projecting Well beyond one end of the cylinder to constitute guides, a cross head reciprocating on the projecting ends of the tie bars and a saw carried by the crosshead, said saw being operatively conneoted to a motor Within the cylinder, a housing i'orniotor valve mechanism secured to the end ofthe motor cylindensaid valve casing and one of the tie bars constituting the handle means of the saw.

FRANK LEsLEY. WEED. 

